Thermoplastic elastomer composition and article produced therefrom

Abstract

A thermoplastic elastomer composition according to the present invention is characterized by comprising: about 100 parts by weight of a styrene-based thermoplastic elastomer; about 8 to about 105 parts by weight of a polyolefin resin; about 45 to about 150 parts by weight of a mineral oil; about 20 to about 105 parts by weight of a vegetable oil; about 30 to about 80 parts by weight of an inorganic filler; about 0.3 to about 3 parts by weight of a thioester-based compound; and about 0.3 to about 3 parts by weight of a hindered phenol-based compound. The thermoplastic elastomer composition has excellent thermal stability, rigidity, low-hardness properties, appearance properties, and eco-friendliness, as well as an excellent balance thereof.

Description

Thermoplastic elastomer composition and molded article manufactured therefrom

[0001] The present invention relates to a thermoplastic elastomer composition and a molded article manufactured therefrom. More specifically, the present invention relates to a thermoplastic elastomer composition exhibiting excellent thermal stability, rigidity, low hardness, appearance, environmental friendliness, and a balance of these properties, and to a molded article manufactured therefrom.

[0002]

[0003] Unlike solid rubbers that are chemically cross-linked, thermoplastic elastomers (TPEs) are physically cross-linked. This allows them to exhibit the elasticity of solid rubbers at room temperature and allow for free extrusion and injection molding. Thermoplastic elastomers are normally composed of long molecules coiled randomly. When a tensile force is applied to a thermoplastic elastomer, the molecules elongate in the direction of the force. When the force is removed, the molecules quickly return to their original, disordered arrangement. Due to the advantages of thermoplastic elastomers, such as easy processability and elastic resilience, demand has rapidly increased as a replacement for non-recyclable rubber, leading to the development of various products. For example, thermoplastic elastomers can be applied to a wide range of applications, including construction gaskets, automotive parts, handles, hoses, cushioning materials, and wire insulators.

[0004] Thermoplastic elastomer compositions may contain oil components to control hardness, moldability, and compression set (C.Set), etc. However, thermoplastic elastomer compositions containing oil components may experience discoloration and deterioration in mechanical properties such as rigidity when continuously exposed to high temperatures.

[0005] Typically, phenolic stabilizers, phosphite stabilizers, etc. can be applied to thermoplastic elastomers to provide thermal stability, but even in this case, there is a concern that only stability is provided during the extrusion stage and thermal stability during the high-temperature aging process is not provided.

[0006] Therefore, there is a need to develop a thermoplastic elastomer composition that has excellent thermal stability, rigidity, low hardness, appearance, environmental friendliness, and a balance of these properties.

[0007] The background technology of the present invention is disclosed in Korean Patent Publication No. 10-2016-0114994, etc.

[0008]

[0009] The purpose of the present invention is to provide a thermoplastic elastomer composition having excellent thermal stability, rigidity, low hardness, appearance, environmental friendliness, and a balance of these properties.

[0010] Another object of the present invention is to provide a molded article formed from the thermoplastic elastomer composition.

[0011] The above and other objects of the present invention can all be achieved by the present invention described below.

[0012]

[0013] 1. One aspect of the present invention relates to a thermoplastic elastomer composition. The thermoplastic elastomer composition comprises: about 100 parts by weight of a styrenic thermoplastic elastomer; about 8 to about 105 parts by weight of a polyolefin resin; about 45 to about 150 parts by weight of a mineral oil; about 20 to about 105 parts by weight of a vegetable oil; about 30 to about 80 parts by weight of an inorganic filler; about 0.3 to about 3 parts by weight of a thioester compound; and about 0.3 to about 3 parts by weight of a hindered phenol compound.

[0014] 2. In the above 1 specific example, the styrene-based thermoplastic elastomer may have a weight average molecular weight of about 100,000 to about 450,000 g / mol.

[0015] 3. In the above 1 or 2 specific examples, the polyolefin resin may include at least one of a propylene homopolymer; a random copolymer in which two or more monomers of propylene, ethylene, butylene, and octene are polymerized; a block copolymer in which ethylene-propylene rubber is blended with polypropylene; an ethylene homopolymer; an ethylene-vinylacetate copolymer; and a copolymer of α-olefin.

[0016] 4. In the above specific examples 1 to 3, the polyolefin resin may have a weight average molecular weight of about 100,000 to about 550,000 g / mol.

[0017] 5. In the above specific examples 1 to 4, the polyolefin resin may have a melt flow index (MI) of about 0.5 to about 40 g / 10 min, measured under conditions of 190°C and 2.16 kg according to ASTM D1238.

[0018] 6. In the above 1 to 5 specific examples, the vegetable oil may include at least one of canola oil, sunflower seed oil, olive oil, castor oil, coconut oil, and grape seed oil.

[0019] 7. In the above 1 to 6 specific examples, the inorganic filler may include at least one of talc, calcium carbonate, clay, wollastonite, mica, whiskers, and glass fibers.

[0020] 8. In the above specific examples 1 to 7, the weight ratio of the thioester compound and the hindered phenol compound may be about 1:0.1 to about 1:3.

[0021] 9. In the above 1 to 8 specific examples, the thermoplastic elastomer composition may have a tensile strength of about 15 to about 50 MPa for a 2 mm thick specimen measured under conditions of 500 mm / min according to ISO 34-1.

[0022] 10. In the above 1 to 9 specific examples, the thermoplastic elastomer composition may have a tensile strength of about 5 to about 20 MPa of a type-1 specimen measured under a condition of 500 mm / min according to ISO 37, and a tensile elongation of about 500 to about 900% of a type-1 specimen measured under a condition of 500 mm / min according to ISO 37.

[0023] 11. In the above 1 to 10 specific examples, the thermoplastic elastomer composition may have a tensile strength retention rate of about 85% or more according to the following formula 1:

[0024] [Formula 1]

[0025] Tensile strength retention rate (%) = (Tensile strength after aging / Tensile strength before aging) × 100

[0026] In the above equation 1, the tensile strength before aging is the tensile strength of a type-1 specimen measured under the condition of 500 mm / min according to ISO 37, and the tensile strength after aging is the tensile strength of the ISO 37 type-1 specimen measured under the condition of 500 mm / min according to ISO 37 after aging for 7 days in an oven at 130°C.

[0027] 12. In the above 1 to 11 specific examples, the thermoplastic elastomer composition may have a tensile elongation retention rate of about 85% or more according to the following formula 2:

[0028] [Formula 2]

[0029] Tensile elongation retention rate (%) = (Tensile elongation after aging / Tensile elongation before aging) × 100

[0030] In the above equation 2, the tensile elongation before aging is the tensile elongation of a type-1 specimen measured under the condition of 500 mm / min according to ISO 37, and the tensile elongation after aging is the tensile elongation of the ISO 37 type-1 specimen measured under the condition of 500 mm / min according to ISO 37 after aging for 7 days in an oven at 130°C.

[0031] 13. In the above 1 to 12 specific examples, the thermoplastic elastomer composition is measured in terms of initial (before aging) color (L0) using a colorimeter for an injection molded specimen having a size of 150 mm × 150 mm × 2 mm. * , a0 * , b0 * ) was measured, and the above specimen was aged in an oven at 130°C for 7 days, and the color (L1) was measured using the same method. * , a1 * , b1 * ) is measured, and the color change (ΔE) calculated according to the following equation 3 may be about 6 or less:

[0032] [Formula 3]

[0033] Color change (ΔE) =

[0034] In the above equation 3, ΔL * L before and after aging * Difference in value (L0 * -L1 * ) and Δa * a before and after aging * Difference in values ​​(a0 * -a1 * ) and Δb * b before and after aging * Difference in values ​​(b0 * -b1 * )am.

[0035] 14. In the above specific examples 1 to 13, the thermoplastic elastomer composition may have a Shore A hardness of about 25 to about 85, measured using a Shore A durometer after overlapping three 2 mm thick specimens according to ISO 868.

[0036] 15. Another aspect of the present invention relates to a molded article. The molded article is characterized in that it is formed from a thermoplastic elastomer composition according to any one of 1 to 14.

[0037]

[0038] The present invention has the effect of providing a thermoplastic elastomer composition having excellent thermal stability, rigidity, low hardness, appearance, environmental friendliness, and balance of physical properties thereof, and a molded article formed therefrom.

[0039]

[0040] Hereinafter, the present invention will be described in detail as follows.

[0041] A thermoplastic elastomer composition according to the present invention comprises (A) a styrenic thermoplastic elastomer; (B) a polyolefin resin; (C) a mineral oil; (D) a vegetable oil; (E) an inorganic filler; (F) a thioester compound; and (G) a hindered phenol compound.

[0042] In this specification, “a to b” indicating a numerical range is defined as “≥a and ≤b”.

[0043]

[0044] (A) Styrenic thermoplastic elastomer

[0045] A styrenic thermoplastic elastomer according to one specific example of the present invention can be applied together with a polyolefin resin, mineral oil, vegetable oil, inorganic filler, thioester compound, hindered phenol compound, etc., to improve the thermal stability, rigidity, low hardness characteristics, appearance characteristics, environmental friendliness, and balance of physical properties of the thermoplastic elastomer composition, and a styrenic block copolymer used in a typical thermoplastic elastomer composition can be used.

[0046] In specific examples, the styrene-based thermoplastic elastomer may be a styrene-butadiene-styrene block copolymer, a styrene-isoprene-styrene block copolymer, a styrene-ethylene-butylene-styrene block copolymer, a styrene-ethylene-propylene-styrene block copolymer, a styrene-butadiene-butylene-styrene block copolymer, or a combination thereof.

[0047] In a specific example, the styrene-based thermoplastic elastomer may have a weight average molecular weight measured by gel permeation chromatography (GPC) of about 100,000 to about 450,000 g / mol, for example, about 150,000 to about 400,000 g / mol. Within this range, the thermoplastic elastomer composition may have excellent mechanical properties, elastic recovery properties, etc.

[0048]

[0049] (B) Polyolefin resin

[0050] A polyolefin resin according to one specific example of the present invention can be applied together with a styrene-based thermoplastic elastomer, mineral oil, vegetable oil, inorganic filler, thioester-based compound, and hindered phenol-based compound, etc., to improve the thermal stability, rigidity, low hardness characteristics, appearance characteristics, environmental friendliness, and physical property balance of the thermoplastic elastomer composition. A polyolefin resin used in a typical thermoplastic resin composition can be used.

[0051] In specific examples, the polyolefin resin may include a propylene homopolymer (homopolypropylene resin); a random copolymer in which two or more monomers of propylene, ethylene, butylene, and octene are polymerized; a block copolymer in which ethylene-propylene rubber is blended with polypropylene; an ethylene homopolymer (homopolyethylene resin); an ethylene-vinylacetate copolymer; a copolymer of α-olefins; a combination thereof, and the like.

[0052] In a specific example, the polyolefin resin may have a weight average molecular weight measured by GPC of about 100,000 to about 550,000 g / mol, for example, about 150,000 to about 500,000 g / mol. Within this range, the mechanical properties, elastic recovery properties, etc. of the thermoplastic elastomer composition may be excellent.

[0053] In a specific example, the polyolefin resin may have a melt flow index of about 0.5 to about 40 g / 10 min, for example, about 0.8 to about 40 g / 10 min, measured under conditions of 190°C and 2.16 kg according to ASTM D1238. Within this range, the moldability of the thermoplastic elastomer composition may be excellent.

[0054] In a specific example, the polyolefin resin may be included in an amount of about 8 to about 105 parts by weight, for example, about 10 to about 100 parts by weight, relative to about 100 parts by weight of the styrenic thermoplastic elastomer. If the content of the polyolefin resin is less than about 8 parts by weight relative to about 100 parts by weight of the styrenic thermoplastic elastomer, there is a concern that thermal stability, rigidity, extrudability, etc. may be reduced, and if it exceeds about 105 parts by weight, there is a concern that the rigidity, low-hardness characteristics (elastic body characteristics), etc. of the thermoplastic elastomer composition may be reduced.

[0055]

[0056] (C) Mineral oil

[0057] According to one specific example of the present invention, a mineral oil can be applied together with a styrene-based thermoplastic elastomer, a polyolefin resin, a vegetable oil, an inorganic filler, a thioester-based compound, a hindered phenol-based compound, etc., to improve the thermal stability, rigidity, low hardness characteristics, appearance characteristics, environmental friendliness, and the balance of physical properties thereof of a thermoplastic elastomer composition. A mineral oil used in a typical thermoplastic elastomer composition can be used.

[0058] In specific examples, the mineral oil may include paraffin oil, naphthene, aromatic compounds, combinations thereof, and the like.

[0059] In a specific example, the mineral oil may have a kinematic viscosity measured at 40°C of about 90 to about 180 cSt, for example, about 100 to about 160 cSt, according to ASTM D445. Within this range, the thermoplastic elastomer composition may have excellent processability, flexibility, etc.

[0060] In a specific example, the mineral oil may be included in an amount of about 45 to about 150 parts by weight, for example, about 50 to about 140 parts by weight, relative to about 100 parts by weight of the styrenic thermoplastic elastomer. If the content of the mineral oil is less than about 45 parts by weight relative to about 100 parts by weight of the styrenic thermoplastic elastomer, there is a concern that thermal stability, extrudability, etc. may deteriorate, and if it exceeds about 150 parts by weight, there is a concern that the appearance characteristics, extrudability, etc. of the thermoplastic elastomer composition may deteriorate.

[0061]

[0062] (D) Vegetable oil

[0063] According to one specific example of the present invention, a vegetable oil is an environmentally friendly material, and can be applied together with a styrene-based thermoplastic elastomer, a polyolefin resin, a mineral oil, an inorganic filler, a thioester-based compound, a hindered phenol-based compound, etc., to provide environmental friendliness to a thermoplastic elastomer composition and improve the thermal stability, rigidity, low hardness characteristics, appearance characteristics, and balance of physical properties thereof of the thermoplastic elastomer composition. As the vegetable oil, a vegetable oil derived from a plant and having a thermal decomposition temperature of about 170 to about 250°C can be used.

[0064] In specific examples, the vegetable oil may include canola oil, sunflower seed oil, olive oil, castor oil, coconut oil, grapeseed oil, combinations thereof, and the like.

[0065] In a specific example, the vegetable oil may have a kinematic viscosity measured at 40°C of about 90 to about 180 cSt, for example, about 100 to about 160 cSt, according to ASTM D445. Within this range, the thermoplastic elastomer composition may have excellent processability, flexibility, etc.

[0066] In a specific example, the vegetable oil may be included in an amount of about 20 to about 105 parts by weight, for example, about 40 to about 100 parts by weight, relative to about 100 parts by weight of the styrenic thermoplastic elastomer. If the amount of the vegetable oil is less than about 20 parts by weight relative to about 100 parts by weight of the styrenic thermoplastic elastomer, there is a concern that the composition may lack environmental friendliness and that thermal stability, extrudability, etc. may deteriorate. If the amount of the vegetable oil is more than about 105 parts by weight, there is a concern that the thermal stability, appearance characteristics, extrudability, etc. of the thermoplastic elastomer composition may deteriorate.

[0067] In a specific example, the weight ratio of the mineral oil and the vegetable oil (mineral oil: vegetable oil) may be from about 1:0.1 to about 1:1.5, for example from about 1:0.3 to about 1:1.2. Within this range, the thermoplastic elastomer composition may have better slip properties, environmental friendliness, etc.

[0068]

[0069] (E) Weapon filler

[0070] An inorganic filler according to one specific example of the present invention can be applied together with a styrene-based thermoplastic elastomer, a polyolefin resin, a mineral oil, a vegetable oil, a thioester-based compound, a hindered phenol-based compound, etc., to improve the thermal stability, rigidity, low hardness characteristics, appearance characteristics, environmental friendliness, and the balance of physical properties thereof of a thermoplastic elastomer composition, and an inorganic filler used in a typical thermoplastic elastomer composition can be used.

[0071] In specific examples, the inorganic filler may include, but is not limited to, talc, calcium carbonate, clay, wollastonite, mica, whiskers, glass fibers, combinations thereof, and the like.

[0072] In a specific example, the inorganic filler may have an average particle size (D50) of about 1.5 to about 3.5 μm, for example, about 1.65 to about 3.5 μm, as measured by a particle size analyzer (manufacturer: Malvern Panalytical Ltd., product name: Mastersizer 3000), a moisture content of about 0.3% or less, and a specific surface area of ​​about 11,500 to about 13,500 cm 3 / g. In the above range, the extrudability, injection property, etc. of the thermoplastic elastomer composition can be excellent.

[0073] In a specific example, the inorganic filler may be included in an amount of about 30 to about 80 parts by weight, for example, about 40 to about 70 parts by weight, relative to about 100 parts by weight of the styrenic thermoplastic elastomer. If the content of the inorganic filler is less than about 30 parts by weight relative to about 100 parts by weight of the styrenic thermoplastic elastomer, there is a concern that the rigidity, etc. may be reduced, and if it exceeds about 80 parts by weight, there is a concern that the thermal stability, rigidity, extrudability, etc. of the thermoplastic elastomer composition may be reduced.

[0074]

[0075] (F) thioester compounds

[0076] A thioester compound according to one specific example of the present invention can be applied together with a styrene-based thermoplastic elastomer, a polyolefin resin, a mineral oil, a vegetable oil, an inorganic filler, and a hindered phenol-based compound, thereby improving the thermal stability, rigidity, low hardness characteristics, appearance characteristics, environmental friendliness, and balance of physical properties of a thermoplastic elastomer composition. A thioester compound used in a typical thermoplastic resin composition can be used.

[0077] In specific examples, the thioester compound may include, but is not limited to, tetrakis[methane-3-(laurylthio)propionate]methane, distearyl thiodipropionate, dilauryl thiodipropionate, tetrakis(methylene-3-dodecylthiopropionate)methane, 2,2-thio-bis{ethyl-b-(3,5-ditertbutyl-4-hydroxyphenyl)}propionate, ditridecyl thiodipropionate, 2,2-bis[[3-dodecylthio]-1-oxopropoxy]methyl]propane-1,3-diyl bis[3-dodecylthio]propionate], combinations thereof, and the like.

[0078] In a specific example, the thioester compound may be included in an amount of about 0.3 to about 3 parts by weight, for example, about 0.4 to about 2 parts by weight, relative to about 100 parts by weight of the styrenic thermoplastic elastomer. If the content of the thioester compound is less than about 0.3 parts by weight relative to about 100 parts by weight of the styrenic thermoplastic elastomer, there is a concern that thermal stability, etc. may be reduced, and if it exceeds about 3 parts by weight, there is a concern that the appearance characteristics, etc. of the thermoplastic elastomer composition may be reduced.

[0079]

[0080] (G) hindered phenolic compounds

[0081] According to one specific example of the present invention, a hindered phenol-based compound can be applied together with a styrene-based thermoplastic elastomer, a polyolefin resin, a mineral oil, a vegetable oil, an inorganic filler, and a thioester-based compound, thereby improving the thermal stability, rigidity, low hardness characteristics, appearance characteristics, environmental friendliness, and physical property balance of the thermoplastic elastomer composition. A hindered phenol-based compound used in a typical thermoplastic resin composition can be used.

[0082] In specific examples, the hindered phenol compounds include pentaerythritol tetrakis(3,5-di-t-butyl-4-hydroxy-hydrocinnamate), triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate, 4,4'-butylidenebis(3-methyl-6-t-butylphenol), 1,6-hexanediol-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)-1,3,5-triazine, pentaerythritol-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,2-Thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2,2-thiobis(4-methyl-6-1-butylphenol), N,N'-hexamethylenebis(3,5-di-t-butyl-4-hydroxy-hydroxycinnamamide), 3,5-di-t-butyl-4-hydroxy-benzylphosphonate-diethyl ester, 1,3,5-trimethyl-2,4,6-tris(3,5-di-butyl-4-hydroxybenzyl)benzene, bis(3,5-di-t-butyl-4-hydroxybenzylsulfonate ethyl calcium, Tris-(3,5-di-t-butyl-4-hydroxybenzyl)-isocyanurate, 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, stearyl-β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2,2'-methylenebis-(4-methyl-6-t-butylphenol), 2,2'-methylene-bis-(4-ethyl-6-t-butylphenol), 4,4'-thiobis-(3-methyl-6-t-butylphenol), octylated diphenylamine, 2,4-bis[(octylthio)methyl]-O-cresol, isooctyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 4,4'-Butylidenebis(3-methyl-6-t-butylphenol, 3,9-bis[1,1-dimethyl-2-[β-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane, 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-trimethyl-2,Examples include, but are not limited to, 4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, bis[3,3'-bis-(4'-hydroxy-3'-t-butylphenyl)butyric acid]glycol ester, 1,3,5-tris(3',5'-di-t-butyl-4'-hydroxybenzyl)-sec-triazine-2,4,6-(1H,3H,5H)trione, d-α-tocopherol, and combinations thereof.

[0083] In a specific example, the hindered phenol compound may be included in an amount of about 0.3 to about 3 parts by weight, for example, about 0.4 to about 2 parts by weight, relative to about 100 parts by weight of the styrenic thermoplastic elastomer. If the content of the hindered phenol compound is less than about 0.3 parts by weight relative to about 100 parts by weight of the styrenic thermoplastic elastomer, there is a concern that thermal stability, etc. may be reduced, and if it exceeds about 3 parts by weight, there is a concern that the appearance characteristics, etc. of the thermoplastic elastomer composition may be reduced.

[0084] In a specific example, the weight ratio of the thioester compound and the hindered phenol compound (thioester compound: hindered phenol compound) may be from about 1:0.1 to about 1:3, for example from about 1:0.4 to about 1:2.5. In this range, the thermal stability, appearance characteristics, etc. of the thermoplastic elastomer composition may be more excellent.

[0085]

[0086] A thermoplastic elastomer composition according to one embodiment of the present invention may further include additives included in conventional thermoplastic elastomer compositions. Examples of the additives include, but are not limited to, flame retardants, anti-drip agents, stabilizers, slip agents, and mixtures thereof. When the additives are used, the content thereof may be about 0.001 to about 40 parts by weight, for example, about 0.1 to about 10 parts by weight, based on about 100 parts by weight of the styrene-based thermoplastic elastomer.

[0087]

[0088] A thermoplastic elastomer composition according to one specific example of the present invention may be in the form of pellets obtained by mixing the above components and melt-extruding them at about 150 to about 250°C, for example, about 170 to about 230°C, using a conventional twin-screw extruder.

[0089] In a specific example, the thermoplastic elastomer composition may have a tensile strength of about 15 to about 50 MPa, for example, about 16 to about 45 MPa, of a 2 mm thick specimen measured under conditions of 500 mm / min according to ISO 34-1.

[0090] In a specific example, the thermoplastic elastomer composition may have a tensile strength of about 5 to about 20 MPa, for example, about 5.5 to about 18 MPa, of a type-1 specimen measured under conditions of 500 mm / min according to ISO 37.

[0091] In a specific example, the thermoplastic elastomer composition may have a tensile elongation of a type-1 specimen measured under conditions of 500 mm / min of about 500 to about 900%, for example, about 550 to about 890%, according to ISO 37.

[0092] In a specific example, the thermoplastic elastomer composition may have a tensile strength retention rate of about 85% or more, for example, about 85 to about 98%, according to the following formula 1.

[0093] [Formula 1]

[0094] Tensile strength retention rate (%) = (Tensile strength after aging / Tensile strength before aging) × 100

[0095] In the above equation 1, the tensile strength before aging is the tensile strength of a type-1 specimen measured under the condition of 500 mm / min according to ISO 37, and the tensile strength after aging is the tensile strength of the ISO 37 type-1 specimen measured under the condition of 500 mm / min according to ISO 37 after aging for 7 days in an oven at 130°C.

[0096] In a specific example, the thermoplastic elastomer composition may have a tensile elongation retention rate of about 85% or more, for example, about 85 to about 98%, according to the following Equation 2.

[0097] [Formula 2]

[0098] Tensile elongation retention rate (%) = (Tensile elongation after aging / Tensile elongation before aging) × 100

[0099] In the above equation 2, the tensile elongation before aging is the tensile elongation of a type-1 specimen measured under the condition of 500 mm / min according to ISO 37, and the tensile elongation after aging is the tensile elongation of the ISO 37 type-1 specimen measured under the condition of 500 mm / min according to ISO 37 after aging for 7 days in an oven at 130°C.

[0100] In a specific example, the thermoplastic elastomer composition is colorimetrically measured for an injection-molded specimen measuring 150 mm × 150 mm × 2 mm in size, with an initial (before aging) color (L0 * , a0 * , b0 * ) was measured, and the above specimen was aged in an oven at 130°C for 7 days, and the color (L1) was measured using the same method. * , a1 * , b1 * ) is measured, and the color change (ΔE) calculated according to the following equation 3 may be about 6 or less, for example, about 1 to about 5.8.

[0101] [Formula 3]

[0102] Color change (ΔE) =

[0103] In the above equation 3, ΔL * L before and after aging * Difference in value (L0 * -L1 * ) and Δa * a before and after aging * Difference in values ​​(a0 * -a1 * ) and Δb * b before and after aging * Difference in values ​​(b0 * -b1 * )am.

[0104] In a specific example, the thermoplastic elastomer composition may have a Shore A hardness of about 25 to about 85, for example, about 25 to about 83, as measured by a Shore A durometer after overlapping three 2 mm thick specimens according to ISO 868. If it is outside the above range, appropriate elasticity may not be obtained, and thus may not be suitable for the use of the present invention.

[0105]

[0106] A molded article according to the present invention is formed from the thermoplastic elastomer composition. The thermoplastic elastomer composition can be manufactured in the form of pellets, and the manufactured pellets can be manufactured into various molded articles (products) through various molding methods such as injection molding, extrusion molding, vacuum molding, and casting molding. Such molding methods are well known to those skilled in the art to which the present invention pertains. The molded article has excellent thermal stability, rigidity, low hardness characteristics, appearance characteristics, environmental friendliness, and a balance of these physical properties, and is useful as sealing parts, shock absorbing parts, and the like, and is particularly useful as construction gaskets, automobile interior parts, tool grips, and home appliance gaskets.

[0107]

[0108] Hereinafter, the present invention will be described in more detail through examples; however, these examples are for the purpose of explanation only and should not be construed as limiting the present invention.

[0109]

[0110] Example

[0111] Below, the specifications of each component used in the examples and comparative examples are as follows.

[0112] (A) Styrenic thermoplastic elastomer

[0113] Styrene-ethylene-butylene-styrene block copolymer (SEBS, manufacturer: Sinopec, product name: YH-503T) was used.

[0114] (B) Polyolefin resin

[0115] Polypropylene resin (propylene-ethylene random copolymer, manufacturer: Lotte Chemical, product name: SB-520, weight average molecular weight: approximately 450,000 g / mol, melt flow index (190°C, 2.16 kg): approximately 1 g / 10 min) was used.

[0116] (C) Mineral oil

[0117] Paraffin oil (Manufacturer: Michang Oil, Product Name: W-1900H) was used.

[0118] (D) Vegetable oil

[0119] (D1) Canola oil (Manufacturer: Lotte Wellfood, Product Name: Canola Oil) was used.

[0120] (D2) Sunflower seed oil (Manufacturer: Lotte Wellfood, Product name: Sunflower Oil) was used.

[0121] (D3) Sunflower seed oil (Manufacturer: Lotte Welfood, Product name: High Oleic Sunflower Oil) was used.

[0122] (E) Weapon filler

[0123] Calcium carbonate (Manufacturer: Omya AG, Product name: Omyacarb 2HB) was used.

[0124] (F) thioester compounds

[0125] 2,2-Bis[[3-dodecylthio]-1-oxopropoxy]methyl]propane-1,3-diyl bis[3-dodecylthio]propionate] (Manufacturer: Adeka Corp., Product name: ADK STAB AO-412S) was used.

[0126] (G) hindered phenolic compounds

[0127] Pentaerythritol-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] (Manufacturer: Songwon Industrial, Product name: SONGNOX 1010) was used.

[0128] (H) Antioxidant

[0129] Phosphite antioxidant (Manufacturer: Adeka Corp., Product name: ADK STAB PEP-36) was used.

[0130] (I) Heat stabilizer

[0131] Copper-based heat stabilizer (Manufacturer: Bruggemann, Product name: Bruggolen TP-H9008) was used.

[0132]

[0133] Examples 1 to 16 and Comparative Examples 1 to 15

[0134] Each of the above components was added in the amounts shown in Tables 1, 2, 3, and 4 below, and then extruded at a barrel temperature of about 210°C to produce pellets. The extrusion was performed using a twin-screw extruder with an L / D of 36 and a diameter of 45 mm, and the produced pellets were dried at about 80°C for about 4 hours or more, and then injection-molded in a 150-ton injection molding machine (cylinder temperature: about 210°C, mold temperature: about 40°C) to produce specimens. The physical properties of the produced specimens were evaluated using the following methods, and the results are shown in Tables 1, 2, 3, and 4 below.

[0135]

[0136] Method of measuring physical properties

[0137] (1) Tear strength (unit: MPa): According to ISO 34-1, the tear strength of a 2 mm thick specimen (ISO 34-1 Fig. 2 standard) was measured at 500 mm / min using a Zwick universal testing machine.

[0138] (2) Tensile strength (unit: MPa): The tensile strength of type-1 specimens was measured under conditions of 500 mm / min using a Zwick universal materials testing machine according to ISO 37.

[0139] (3) Tensile elongation (unit: %): The tensile elongation of type-1 specimens was measured under conditions of 500 mm / min using a Zwick universal testing machine according to ISO 37.

[0140] (4) Tensile strength retention rate (unit: %): The tensile strength retention rate was calculated according to Equation 1 below.

[0141] [Formula 1]

[0142] Tensile strength retention rate (%) = (Tensile strength after aging / Tensile strength before aging) × 100

[0143] In the above equation 1, the tensile strength before aging is the tensile strength of a type-1 specimen measured under the condition of 500 mm / min according to ISO 37, and the tensile strength after aging is the tensile strength of the ISO 37 type-1 specimen measured under the condition of 500 mm / min according to ISO 37 after aging for 7 days in an oven at 130°C.

[0144] (5) Tensile elongation retention rate (unit: %): The tensile elongation retention rate was calculated according to Equation 2 below.

[0145] [Formula 2]

[0146] Tensile elongation retention rate (%) = (Tensile elongation after aging / Tensile elongation before aging) × 100

[0147] In the above equation 2, the tensile elongation before aging is the tensile elongation of a type-1 specimen measured under the condition of 500 mm / min according to ISO 37, and the tensile elongation after aging is the tensile elongation of the ISO 37 type-1 specimen measured under the condition of 500 mm / min according to ISO 37 after aging for 7 days in an oven at 130°C.

[0148] (6) Color change (ΔE): The initial (before aging) color (L0) of the injection molded specimen measuring 150 mm × 150 mm × 2 mm was measured using a colorimeter. * , a0 * , b0 * ) was measured, and the above specimen was aged in an oven at 130°C for 7 days, and the color (L1) was measured using the same method. * , a1 * , b1 * ) was measured, and the color change (ΔE) was calculated according to Equation 3 below.

[0149] [Formula 3]

[0150] Color change (ΔE) =

[0151] In the above equation 3, ΔL * L before and after aging * Difference in value (L0 * -L1 * ) and Δa * is a before and after aging * Difference in values ​​(a0 * -a1 * ) and Δb * b before and after aging * Difference in values ​​(b0 * -b1 * )am.

[0152] (7) Hardness: According to ISO 868, three 2 mm thick specimens were overlapped and the Shore A hardness was measured using a Shore A durometer.

[0153] (8) Appearance characteristics evaluation: The blooming phenomenon (a phenomenon in which components such as oil seep to the surface and patterns appear or color changes) on the surface of an injection molded specimen measuring 150 mm × 150 mm × 2 mm was visually confirmed.

[0154] (9) Environmental friendliness evaluation: Evaluation was conducted based on the use of environmentally friendly materials (vegetable oil). (○: Use of environmentally friendly materials, ×: No use of environmentally friendly materials)

[0155]

[0156] Example 12345678 (A) (parts by weight) 100100100100100100100100 (B) (parts by weight) 105010066.766.766.766.766.7 (C) (parts by weight) 100100100507510011060 (D1) (parts by weight) 50505010075504090 (D2) (parts by weight) -------- (D3) (parts by weight) -------- (E) (parts by weight) 555555555555555 (F) (parts by weight) 11111111 (G) (parts by weight) 11111111 (H) (parts by weight) -------- (I) (by weight)--------Tear strength16.237.344.236.336.936.836.835.4Tensile strength5.512.114.211.812.112.412.211.7Tensile elongation881.3833.0787.6870.0845.2834.2833.8865.2Tensile strength retention91.892.291.691.892.793.493.690.9Tensile elongation retention92.593.591.892.692.993.293.991.8Color change (ΔE)4.54.64.44.94.63.73.54.7Shore A Hardness 25.368.782.865.766.066.767.166.4 Surface blooming ××××××××× Eco-friendliness ○○○○○○○○

[0157]

[0158] Example 910111213141516(A) (parts by weight)100100100100100100100100100(B) (parts by weight)66.766.766.766.766.766.766.766.766.7(C) (parts by weight)100100100100100100100100(D1) (parts by weight)--505050505050(D2) (parts by weight)50-------(D3) (parts by weight)-50------(E) (parts by weight)5555407055555555(F) (parts by weight)11110.4211(G) (parts by weight)1111110.42(H) (parts by weight)--------(I) (by weight)--------Tear strength36.837.436.438.237.036.537.036.5Tensile strength11.812.311.313.511.711.411.711.4Tensile elongation826.1835.1855.2787.9828.3820.6828.3820.6Tensile strength retention91.794.892.091.786.795.886.795.8Tensile elongation retention92.296.793.591.985.395.685.395.6Color change (ΔE)4.42.93.83.65.62.75.62.7Shore A Hardness 68.668.971.065.468.468.068.468.0Surface blooming ×××××××××Eco-friendliness ○○○○○○○○

[0159]

[0160] Comparative Example 1234567 (A) (parts by weight) 100100100100100100100 (B) (parts by weight) 511066.766.766.766.766.7 (C) (parts by weight) 10010040160100100100 (D1) (parts by weight) 50505050-11050 (D2) (parts by weight)------- (D3) (parts by weight)------- (E) (parts by weight) 5555555555590 (F) (parts by weight) 1111111 (G) (parts by weight) 1111111 (H) (parts by weight)------- (I) (by weight)-------Tear strength 13.249.238.834.239.230.314.8Tensile strength 4.618.816.710.517.910.74.5Tensile elongation 900.4401.2570.8840.2580.4850.9480Tensile strength retention 90.691.884.390.183.687.391.2Tensile elongation retention 90.492.684.790.887.286.990.6Color change (ΔE) 4.64.56.13.54.57.84.6Shore A hardness 20.895.077.960.278.263.767.8Surface blooming Whether×××○×○×Eco-friendliness○○○○×○○

[0161]

[0162] Comparative Example 89101112131415(A) (parts by weight)100100100100100100100100100(B) (parts by weight)66.766.766.766.766.766.766.766.766.7(C) (parts by weight)100100100100100100100100100(D1) (parts by weight)5050505050505050(D2) (parts by weight)--------(D3) (parts by weight)--------(E) (parts by weight)555555555555555(F) (parts by weight)0.13.511--11(G) (parts by weight)110.13.511--(H) (parts by weight)----1-1-(I) (by weight)-----1-1Tear strength36.837.435.936.937.537.237.037.6Tensile strength13.113.612.713.312.212.012.112.4Tensile elongation845.3840.8842.9846.2829.6827.4825.4830.8Tensile strength retention86.294.580.392.378.774.877.971.8Tensile elongation retention88.294.281.792.491.788.690.489.2Color change (ΔE)10.83.24.64.136.137.419.335.8Shore A Hardness 67.267.768.367.569.068.569.268.7 Surface blooming ×○×○××××× Eco-friendliness ○○○○○○○○

[0163]

[0164] From the above results, it can be seen that the thermoplastic elastomer composition of the present invention is environmentally friendly by applying vegetable oil, which is an environmentally friendly material, and has excellent thermal stability (tear strength, tensile strength retention, tensile elongation retention, color change), rigidity (tensile strength, tensile elongation), low hardness characteristics (Shore A hardness), appearance characteristics (whether surface blooming occurs), and a balance of these physical properties.

[0165] On the other hand, in the case of Comparative Example 1 in which the content of the polyolefin resin is less than the range of the present invention, it can be seen that the thermal stability, rigidity, etc. are reduced, and in the case of Comparative Example 2 in which the content of the polyolefin resin exceeds the range of the present invention, it can be seen that the rigidity, low hardness characteristics, etc. are reduced. In the case of Comparative Example 3 in which the content of the mineral oil is less than the range of the present invention, it can be seen that the thermal stability, etc. are reduced, and in the case of Comparative Example 4 in which the content of the mineral oil exceeds the range of the present invention, it can be seen that the appearance characteristics, etc. are reduced, and in the case of Comparative Example 5 in which vegetable oil was not applied, it can be seen that the environmental friendliness was not obtained and the thermal stability, etc. are reduced, and in the case of Comparative Example 6 in which the content of the vegetable oil exceeds the range of the present invention, the thermal stability, appearance characteristics, etc. are reduced. In the case of Comparative Example 7 in which the content of the inorganic filler exceeds the range of the present invention, it can be seen that the thermal stability, rigidity, etc. are reduced. In the case of Comparative Example 8, where the content of the thioester compound is less than the range of the present invention, it can be seen that the thermal stability, etc. are deteriorated. In the case of Comparative Example 9, where the content of the thioester compound exceeds the range of the present invention, it can be seen that the appearance characteristics, etc. are deteriorated. In the case of Comparative Example 10, where the content of the hindered phenol compound is less than the range of the present invention, it can be seen that the thermal stability, etc. are deteriorated. In the case of Comparative Example 11, where the content of the hindered phenol compound exceeds the range of the present invention, it can be seen that the appearance characteristics, etc. are deteriorated. In addition, in the case of Comparative Examples 12 and 13, where a phosphite-based antioxidant (H) or a copper-based thermal stabilizer (I) is applied instead of the thioester-based compound of the present invention, and in the case of Comparative Examples 14 and 15, where a phosphite-based antioxidant (H) or a copper-based thermal stabilizer (I) is applied instead of the hindered phenol-based compound of the present invention, it can be seen that the thermal stability, etc. are deteriorated.

[0166]

[0167] The present invention has been described with reference to exemplary embodiments. Those skilled in the art will appreciate that the present invention can be implemented in modified forms without departing from its essential characteristics. Therefore, the disclosed embodiments should be considered illustrative rather than limiting. The scope of the present invention is set forth in the claims, not the foregoing description, and all differences within the scope equivalent thereto should be construed as being encompassed by the present invention.

Claims

1. About 100 parts by weight of styrene-based thermoplastic elastomer; About 8 to about 105 parts by weight of polyolefin resin; About 45 to about 150 parts by weight of mineral oil; About 20 to about 105 parts by weight of vegetable oil; About 30 to about 80 parts by weight of inorganic filler; About 0.3 to about 3 parts by weight of a thioester compound; and A thermoplastic elastomer composition comprising about 0.3 to about 3 parts by weight of a hindered phenolic compound.

2. A thermoplastic elastomer composition according to claim 1, characterized in that the styrene-based thermoplastic elastomer has a weight average molecular weight of about 100,000 to about 450,000 g / mol.

3. A thermoplastic elastomer composition according to claim 1 or 2, wherein the polyolefin resin comprises at least one of a propylene homopolymer; a random copolymer in which two or more monomers of propylene, ethylene, butylene, and octene are polymerized; a block copolymer in which ethylene-propylene rubber is blended with polypropylene; an ethylene homopolymer; an ethylene-vinylacetate copolymer; and a copolymer of α-olefin.

4. A thermoplastic elastomer composition according to any one of claims 1 to 3, wherein the polyolefin resin has a weight average molecular weight of about 100,000 to about 550,000 g / mol.

5. A thermoplastic elastomer composition according to any one of claims 1 to 4, wherein the polyolefin resin has a melt flow index of about 0.5 to about 40 g / 10 min, measured under conditions of 190°C and 2.16 kg according to ASTM D1238.

6. A thermoplastic elastomer composition according to any one of claims 1 to 5, wherein the vegetable oil comprises at least one of canola oil, sunflower seed oil, olive oil, castor oil, coconut oil, and grape seed oil.

7. A thermoplastic elastomer composition according to any one of claims 1 to 6, wherein the inorganic filler comprises at least one of talc, calcium carbonate, clay, wollastonite, mica, whiskers, and glass fibers.

8. A thermoplastic elastomer composition according to any one of claims 1 to 7, characterized in that the weight ratio of the thioester compound and the hindered phenol compound is about 1:0.1 to about 1:

3.

9. A thermoplastic elastomer composition according to any one of claims 1 to 8, characterized in that the thermoplastic elastomer composition has a tensile strength of about 15 to about 50 MPa of a 2 mm thick specimen measured under conditions of 500 mm / min according to ISO 34-1.

10. A thermoplastic elastomer composition according to any one of claims 1 to 9, characterized in that the tensile strength of a type-1 specimen measured under a condition of 500 mm / min according to ISO 37 is about 5 to about 20 MPa, and the tensile elongation of a type-1 specimen measured under a condition of 500 mm / min according to ISO 37 is about 500 to about 900%.

11. A thermoplastic elastomer composition according to any one of claims 1 to 10, characterized in that the thermoplastic elastomer composition has a tensile strength retention rate of about 85% or more according to the following formula 1: [Formula 1] Tensile strength retention rate (%) = (Tensile strength after aging / Tensile strength before aging) × 100 In the above equation 1, the tensile strength before aging is the tensile strength of a type-1 specimen measured under the condition of 500 mm / min according to ISO 37, and the tensile strength after aging is the tensile strength of the ISO 37 type-1 specimen measured under the condition of 500 mm / min according to ISO 37 after aging for 7 days in an oven at 130°C.

12. A thermoplastic elastomer composition according to any one of claims 1 to 11, characterized in that the thermoplastic elastomer composition has a tensile elongation retention rate of about 85% or more according to the following formula 2: [Formula 2] Tensile elongation retention rate (%) = (Tensile elongation after aging / Tensile elongation before aging) × 100 In the above equation 2, the tensile elongation before aging is the tensile elongation of a type-1 specimen measured under the condition of 500 mm / min according to ISO 37, and the tensile elongation after aging is the tensile elongation of the ISO 37 type-1 specimen measured under the condition of 500 mm / min according to ISO 37 after aging for 7 days in an oven at 130°C.

13. In any one of the first to 12th paragraphs, the thermoplastic elastomer composition has an initial (before aging) color (L0) measured by a colorimeter for an injection molded specimen measuring 150 mm × 150 mm × 2 mm in size. * , a0 * , b0 * ) was measured, and the above specimen was aged in an oven at 130°C for 7 days, and the color (L1) was measured using the same method. * , a1 * , b1 * ) and then a thermoplastic elastomer composition characterized in that the color change (ΔE) calculated according to the following equation 3 is about 6 or less: [Formula 3] Color change (ΔE) = In the above equation 3, ΔL * L before and after aging * Difference in value (L0 * -L1 * ) and Δa * is a before and after aging * Difference in values ​​(a0 * -a1 * ) and Δb * b before and after aging * Difference in values ​​(b0 * -b1 * )am.

14. A thermoplastic elastomer composition according to any one of claims 1 to 13, characterized in that the thermoplastic elastomer composition has a Shore A hardness of about 25 to about 85 as measured by a Shore A durometer after overlapping three 2 mm thick specimens according to ISO 868.

15. A molded product characterized by being formed from a thermoplastic elastomer composition according to any one of claims 1 to 14.

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